Safety device for boosters.



No; 838,407. P'ATENI'ED DEC. 11, 1906.

J. D. HILLIARDJR. SAFETY DEVICE FOR BOOSTERS.

APPLICATION FILED JULY 2, 1904.

Inventor: John D. Hilliard Jn THE mmms PETERS 00., WASHINGTON. n. c.

UNITED STATES PATENT OFFICE.

JOHN D. HILLIARD, JR, OF GLENS FALLS, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SAFETY DEVICE FOR BOOSTERS.

Specification of Letters Patent.

Patented Dec. 11, 1906.

Application filed July 2, 1904. Serial No. 215,113-

Glens Falls, county of Warren, State of N ew York, have invented certain new and useful Improvements in Safety Devices for Boosters, of which the following is a specification.

This invention relates to systems of transmission of electric current, and especially to those in which a booster is employed.

In operating constant-potential systems it is frequently desirable to raise the potential on one or more particular feeders either to compensate for an excessive drop due to the length of the feeder or for greater than normal drop due to a temporary or periodical increase of load. For this purpose a device commonly known as a booster is employed, consisting of a generator in series with the line driven by a motor connected across the line. If in such an organization the motor circuit be opened, either by reason of an overload or any other cause, or if the belt or shaft connecting the motor and generator breaks, the generator will stop; but because it is connected with the line it will immediately start again in the opposite direction and run as a series motor. Since it has no load, it will rapidly accelerate in speed until it is torn to pieces by centrifugal force.

The object of my invention is to prevent such a catastrophe. To this end I provide means for automatically opening the main circuit the instant the booster reverses its direction of rotation. This is preferably ac complished by providing the main-line circuit-breaker with a tripping-coil included in a shunt across the line, the shunt being normally open, but closable by means of a switch, which is held normally open by frictional contact with a rotating portion of the generator part of the booster. A reversal of the normal direction of rotation causes the switch to close, thereby closing the shunt, energizing the tripping-coil, and causing the circuit-breaker to open.

In th accompanying drawings, Figure 1 is an end elevation of a pillow-block, shaft, and shaft-bearing of a booster equipped with my invention; and Fig. 2 is a diagram of circuits.

The shaft 1 of the booster is suitably journaled in a bearing 2, supported. on a pillowblock 3. Proiecting from the bearing is a stud 4, on which is pivoted a switch-lever 5, the stud preferably engaging with a slot 6 in said lever in order to afford considerable play therefor. The inner end of the lever is in frictional contact with the shaft 1 and may be shod with leather 7, if desired. A spring 8 v is attached at its lower end to the stud and at the upper end to the lever and serves to keep the lever pressed against the shaft. The outer end of the lever carries an insulated contact-blade 9. Secured to the bearing is a standard 10, which supports the two terminals 11 12 of the shunt-circuit arranged to be bridged by the blade 9 when the lever closes upon them.

The shaft rotates normally in the direction of the arrow, so that the lever is held in an upright position against'the fixed stop 13, which is located somewhat above the stud; but if for any reason the direction of rotation of the shaft is reversed the lower end of the lever is carried with it and the upper end swings over (to the-left in Fig. 1) until the contact-blade 9 bridges the two contacts 11 12. By referring to Fig. 2 it will be seen that this operation closes the shunt 14 across the mains 15 and energizes the tripping-coil 16 of the circut-breaker 17 in the main line. The mains 15 are supplied with carrent from the generator 18, and at 19 is the generator end of the series-wound booster in series with the line and driven by the shunt-wound motor 20, connected across the mains and controlled by a switch 21. It will thus be seen that whenever the booster starts to run away from any cause whatever the switch will close at the instant the booster-shaft reverses, and thus open the main line and prevent any damage.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In an electric transmission system, the combination of a generator, a supply-circuit fed thereby, a booster included in said circuit, and means operated by the booster for IOK) breaking said circuit upon a reversal in the direction of rotation of said booster.

2 In an electric transmission system, the combination of a generator, a supply-circuit fed thereby, a booster included in said circuit, a circuit-breaker also included in. said circuit, and means actuated by said booster upon a reversal in the direction oi rotation of said. booster to trip said circuit-breaker to open said circuit.

3. In an electric transmission system, the combination of a generator, a supply-circuit ied thereby, a booster included in said circuit, a circuit-breaker also included in said circuit, and means comprising a friction device in contact with a rotating part of the booster for tripping said circuit-breaker upon a reversal in the direction of rotation of said rotating part.

L. The combination with a series-wound booster, of a switch-lever pivoted in proximity to the shaft of said booster and in frictional contact therewith, and a stop against which said lever is held by the rotation of the shaft in its normal direction.

5. The combination with a series-Wound booster, of a switchlever pivoted in proximity to the shaft of said booster, a spring urging the end of said lever into frictional contact with said shaft, and a stop limiting the movement 01 said lever in the direction in which it tends to move when the shaft rotates in its normal direction.

6. The combination with a series-wound booster, of a switch-lever having a slot, a fixed stud engaging with said slot, a spring attached to the stud and the lever, and a fixed stop for the lever, the end of said lever being in frictional contact with the shaft ol the booster.

7. The combination with supply-mains, of a circuit-breaker controlling the same, a normally open shunt including a tripping-coil of said circuit-breaker, and a booster provided with a switch operating to close said shunt when the booster reverses its direction of rotation.

S. The combination with su1')ply-maius, of a circuit-breaker controlling the same, a normally open. shunt including a tripping-coil of said circuit-breaker, a booster in circuit with said mains, and a switch operated by a movable part of the booster to close said shunt upon a reversal of the normal direction of rotation ol said booster.

In witness whereof I have hereunto set my hand this 30th day of June, 1904.

JOHN D. HlLLlAlil), Jn.

Witnesses C. M. DooLrrrLn, J. M. SEAY. 

